1. Field of the Invention
The invention relates to the field of vehicle braking methods and apparatus. More specifically, the invention is a method and adapter apparatus for enhancing the braking efficiency of existing vehicle braking systems of the disc type.
2. Description of the Related Art
In the field of automotive braking a common brake type is a disc brake. In this type of brake, a rotating disc, connected to rotate at the speed of an associated wheel or axle, is engaged by a friction pad or pads pressing against opposed surfaces of the rotating disc. The pad or pads are pressed or clamped against the respective disc surfaces by an associated hydraulically, mechanically, or electrically actuated caliper. The caliper is fixed with respect to the rotation of the friction disc and is positioned in close proximity to the disc so that the friction pads travel a minimal distant prior to engagement with the disc surface.
In the case of any configuration of a disc type brake, the size of the disc (both thickness and diameter) and associated frictions pads and caliper are selected according to the anticipated service environment of the brake. A particular braking torque is necessary to stop the vehicle under control and within reasonable distances. The brake torque is developed as a function of friction, between the braking pads and the friction disc, developed at a selected distance from the rotational axis of the friction disc. Since the braking torque is created as a result of friction, heat is also created. The entire braking system converts the rotational energy of the disc into heat energy that is absorbed and dissipated through the disc and caliper to their respective mountings and ambient surrounding air or other auxiliary cooling. If the braking system is excessively used compared to its anticipated design use, the heat absorbed can lead to failure of braking.
In order to improve braking efficiency of a given braking system, the capacity of the system to create braking torque and to absorb and dissipate heat should be increased. In the automotive aftermarket field a number of brake equipment suppliers provide brake improvement kits adapted for retrofit to existing braking systems. These kits can include different friction pads or discs adapted to create more braking torque and to absorb and discard heat more effectively. The friction pads may have a higher friction co-efficient against the disc and/or the discs may be thicker, internally vented, or larger in diameter. Many of these kits often include different calipers as well. The calipers are usually designed to accommodate friction pads having a larger surface area, thicker disc and pad configurations, and/or larger diameter disc sizes.
In the situation where larger diameter discs are provided, two effects occur with respect to braking performance. One, the friction disc is physically larger and more robust and accordingly has the potential, depending on material selection, to absorb and discard more heat. Two, owing to the larger diameter, the distance from the disc rotational axis to the center of pressure of the friction pads is increased resulting in enhanced braking torque for a given level of friction pad pressure and engagement.
Many of these aftermarket brake improvement kits work to the extent the overall capacity of the brake system to absorb and discard heat is enhanced and a greater level of available brake torque is provided. However, the expense of the respective parts and labor can be quite high and the skill required to adapt the aftermarket mechanisms to the various vehicle fitments can be considerable. In addition, once the different calipers and friction pads are mounted, the various replacement parts needed as a result of ordinary wear can only be supplied according to the specifications of the particular kit installed. In these situations, the relative scarcity of parts can remove a vehicle from service for considerable periods.